Dealing With Hydro-Geological Events: Mitigation and History Cases

Past Damaging Hydrogeological Events (DHEs), which can be defined as periods characterised by heavy rainfall inducing such damaging phenomena as landslides and floods, are analysed in this article. The work is focused on the relationships between these phenomena and the characteristics of triggered rainfall, to supply useful suggestions for early detection and damage mitigation. The analysis of past DHEs allows for the characterisation of the main types of DHEs, which affected a selected area in the past and could affect it again in the future. The proposed characterisation is based on triggering scenarios (meteorological conditions preceding the occurrence of DHEs), DHE's effects (damage caused by landslides and floods) and triggering factors (rainfall of different durations). Based on these features, the typical DHEs affecting a study area can be outlined and ranked according to their severity, thus specific emergency management can be planned to successfully manage them. To obtain results that have a reliable statistical meaning, a large amount of data of three different types (meteorological, rainfall and damage data) must be treated, and some indices, allowing the comparative analysis of these kinds of data, have to be introduced. In this work we describe the methodological approach, which can be applied in different climatic and anthropogenic contexts;finally, some applications of the proposed method to the region of Calabria (South Italy) are presented